PERFUMES AND THEIR PREPARATION. 313

hot and sometimes sour food, in .part in the lack of attention
bestowed- on the care of the mouth by many people. The
care of the mouth is most important after meals and in the
morning; particles of food lodge even between the most per-
fect teeth and undergo rapid decomposition in the high tem-
perature prevailing in the mouth. This gives rise to a most
disagreeable odor, and the decomposition quickly extends to
the teeth.

Perfectly normal healthy teeth consist of a hard, brilliant
external coat, the enamel, which opposes great resistance to
acid and decomposing substances. But unfortunately the
enamel is very sensitive to changes of temperature and easily
cracks, thus admitting to the bony part of the teeth suck
deleterious substances and leading to their destruction. The
bulk of the tooth consists of a porous mass of bone which is
easily destroyed, and thus the entire set may be lost.

Hygienic perfumery is able to offer to the public means by
which a healthy set of teeth can be kept in good condition
and the disease arrested in affected teeth,, and by which an
agreeable freshness is imparted to the gums and lips. While
true perfumes may be looked upon as more or less of a lux-
ury, the hygiene of the mouth is a necessity; for we have to
deal with the health and preservation of the important masti-
catory apparatus which is necessary to the welfare of the
whole body, so that the aesthetic factor occupies a secondary
position, or rather results as a necessary consequence from a
proper care of the mouth.

With no other hygienic article have so many sins been
committed as with those intended for the teeth; we have had
occasion to examine a number of tooth powders, some of them
very high-priced, which were decidedly injurious. Thus we
have known of cases in which powdered pumice stone, colored
and perfumed, has been sold as a tooth powder. Pumice
stone, however, resembles glass in its composition and acts on